Taenia Infection Clinical Presentation

Updated: Oct 06, 2015
  • Author: Sowmya Nanjappa, MD; Chief Editor: Russell W Steele, MD  more...
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Presentation

History

Taeniasis

Most individuals with taeniasis are either asymptomatic or have mild-to-moderate complaints.

The most common complaint is passage (active or passive) of proglottids, which is associated with slight discomfort. Other symptoms include the following:

  • Colicky abdominal pain (more common in children)
  • Nausea
  • Weakness
  • Loss of appetite
  • Increased appetite
  • Headache
  • Constipation
  • Dizziness
  • Diarrhea
  • Pruritus ani
  • Hyperexcitability

Abdominal pain and nausea are reportedly more common in the morning and are characteristically relieved by eating small amounts of food. Children are more symptomatic than adults and often manifest change of appetite, both increased and decreased. Symptoms in infants are more pronounced and consist of vomiting, diarrhea, fever, weight loss, and irritability.

The most common serious complication of adult tapeworm infection is appendicitis. Other reported complications include obstruction of bile ducts, pancreatic duct and tapeworm growth in ectopic locations (eg, middle ear, adenoid tissue, uterine cavity). A mild eosinophilia of 5-15% may occur in 5-45% of patients; higher levels are rare.

Cysticercosis and neurocysticercosis (NCC)  [15]

In cysticercosis, the cysticerci are most often located in subcutaneous and intermuscular tissues, followed by the eye and then the brain. The CNS is involved in 60-90% of patients (ie, NCC). Most patients have more than one cyst; as many as 200 cysts have been reported.

NCC symptoms include 3 characteristic syndromes: convulsions and/or seizures, intracranial hypertension, and psychiatric disturbances, which may occur separately or simultaneously. [16] Onset can be insidious (eg, elevated intracranial pressure) or abrupt (eg, floating cysticerci suddenly block cerebrospinal fluid [CSF]). See the following:

  • Convulsions and/or seizures: Seizures are caused by the localization of cysticerci in brain parenchyma. Children most often present with seizures, which are focal with acute onset. Cysticercosis is the most common cause of epilepsy in endemic areas [17] and is the sole manifestation in as many as one third of patients. [18]
  • Intracranial hypertension: This is caused by obstruction of CSF by intraventricular brain cysts. Symptoms include headache, nausea, vomiting, vertigo, and papilledema.
  • Psychiatric disturbances: Although changes in personality and mental status occur more often in adults than in children, behavioral changes and learning disabilities were reported in a study of 25 affected children. [19]

NCC must be differentiated from severe cysticercal meningitis, a syndrome reminiscent of bacterial, tuberculous, or amebic meningitis. [20]

Other possible infections

See the list below:

  • Ocular cysticercosis: The subretinal space, vitreous, and conjunctiva are the most frequent sites of infection. Common manifestations of infection include severe pain and blurred or lost vision.
  • Muscular and dermatologic cysticercosis: Cysticerci in muscles often are associated with NCC. Any muscle mass may be involved and appear as acute myositis. However, most patients are asymptomatic. Subcutaneous nodules may be evident.
  • Coenurosis: Clinical manifestations are determined by the site of the coenurus larvae. Patients with cerebral coenurosis can present with seizure or intracranial hypertension. Ocular coenurosis manifests as a red and painful eye.
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Physical

Most children with intestinal taeniasis appear healthy. Physical findings may include the following:

  • Weight loss, caused by loss of appetite, is more pronounced in infants than in adults.
  • Subcutaneous nodules are less common in children than in adults.
  • Neurologic abnormalities in some children with NCC may manifest as hemiparesis, sensory disturbances, and papilledema.
  • Intraocular larva may be evident.
  • Muscular pseudohypertrophy may occur.
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Causes

Taeniasis is caused by ingesting inadequately cooked beef or pork that contains the larvae or cysticerci of T saginata or T solium. Cysticercosis, which is caused by ingesting eggs of T solium, occurs when larvae are deposited in skeletal muscle, brain, eyes, and other organs. Taeniasis is endemic in countries where both T saginata and T solium are common and public hygiene is poor. A species of Taenia recently identified in many Southeast Asian countries resembles T saginata at the molecular level, and its ingestion in inadequately cooked pork causes an intestinal infection. This close relationship with T saginata has led to the assumption that it does not cause human cysticercosis because human cysticercosis is caused almost exclusively by T solium.

Coenurosis results when humans accidentally ingest mature T multiceps or T serialis eggs, usually in contaminated fruits or vegetables. Approximately 100 cases of coenurosis have been reported, primarily in tropical Africa, with the remainder in North and South America and South Africa. Interestingly, the cases in central Africa rarely involved the CNS, whereas more than 75% of the cases elsewhere had CNS involvement. Larvae of these species may be inoculated directly into a child's conjunctiva and skin as the child plays on contaminated ground.

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